(a) Field of the Invention
The present invention relates to a system and a method for moving workpieces in and out of a manufacturing process. More specifically, the present invention relates to a system and a method for moving workpieces in and out of a manufacturing process for a semiconductor or a thin film transistor liquid crystal display (TFT-LCD).
(b) Description of the Related Art
Currently, most TFT-LCD manufacturing processes are automated to enhance productivity. Therefore, when processing substrates in a specific process apparatus used for this purpose, a cassette that stores the substrates to be processed is transferred to the process apparatus by an automated guided vehicle (AGV) and is then loaded into the process apparatus. The substrates in the cassette undergo various processes in the process apparatus.
Although the above processes are automated, when a problem occurs in the process apparatus, an operator must be able to check the status of the process apparatus. In this case, the substrates are transferred to the process apparatus in a cassette by a manually guided vehicle (MGV) that the operator manually operates.
Therefore, in the conventional substrate manufacturing process, the way of processing the substrates depends upon which transfer device (AGV or MGV) is used to transfer the cassette to the process apparatus. That is, when transferring the cassette to the process apparatus using the AGV (hereinafter referred to as an “AGV mode”), job processes on the substrates in each portion of the process apparatus including cassette loading are almost entirely performed automatically. On the other hand, when transferring the cassette to the product process apparatus using the MGV (hereinafter referred to as an “MGV mode”), job processes on the substrate in each process apparatus are manually or automatically performed according to the needs of the operator.
However, in the conventional substrate transfer systems, cassettes can be moved in and out of the process apparatus using only a transfer device that corresponds to the transfer mode set in the manufacturing process apparatus. Using a transfer device that does not correspond to the set transfer mode causes an error.
Therefore, in the conventional substrate transfer systems, the transfer mode set in the process apparatus is checked, and the cassette is then moved using the transfer device corresponding to this transfer mode. This is a cumbersome process resulting in a decrease in overall productivity.